The Creatures that We Are is a Manga/Manhwa/Manhua in english language, MONSTERS series, english chapters have been translated and you can read them here. You are reading chapters on www.mgeko.nl fastest updating comic site. The Summary is

Gao Yang, an orphan, crosses over to a "parallel world" at the age of six and starts living in a warm family of five. At the age of eighteen, Gao Yang accidentally discovers the true nature of the world: it's not a parallel world at all but a mysterious realm, and the family and friends around him are all terrifying "beasts"!